1. Field of the Invention
The present invention relates to processing Session Initiation Protocol (SIP) signaling in a voice/data integrated switching system, and more particularly, to processing SIP signaling in a voice/data integrated switching system, in which networking is realized by signaling using a Voice over Internet Protocol (VoIP) SIP between a voice data switching system and a terminal in a voice/data integrated switching system including a data switch module and a router in a private switch.
2. Description of the Related Art
Internet Protocol (IP) networks are improving performance and service due to a rapid spread of the Internet and requirements for a variety of services. Accordingly, requirements for more services are rising in the market.
Voice transmission using an IP network, together with data transmission, plays an important role in the IP network, and accordingly, there is a need for a variety of voice transmission functions. Furthermore, integration of an existing terminal communication and VoIP using a digital telephone and a single telephone is needed.
Therefore, there is a need for a terminal which can be used in the IP network and has the same shape and operation as existing digital telephones such that it meets various needs. An Internet phone was developed in response to this need.
In general, an Internet phone communicates with a switch using an ITU-T recommendation H.323 protocol. The H.323 protocol is used for multimedia communication such as voice, image and data.
An IP-based voice communication system includes a voice switch, a data switch and a router.
The data switch switches the voice data, converted into packet data in the voice switch, to the router. The data switch includes an Ethernet switch.
The router transmits the voice packet data, switched in the data switch, to the Internet network.
The voice switch includes: an office line match module to match with an office line, i.e., a Public Switched Telephone Network (PSTN); an extension subscriber match module to match with an extension subscriber terminal; a Time Division Multiplexing (TDM) switching module to respectively divide a plurality of voice signals into predetermined time slots, and to transmit the divided signals; a media gateway module to convert a Pulse Code Modulation (PCM) voice signal transmitted from the TDM switching module into voice packet data, and to convert the voice packet data received from the data switch into the PCM voice signal; and a control module to control each of the modules. The media gateway module, the TDM switching module, the extension subscriber module and the office line match module are connected to one another using a PCM serial bus, and the control module is connected to each of the modules using a Central Processing Unit (CPU) bus. That is, the media gateway module in the voice switch compresses an existing PCM converted voice signal into packets, transmits the packets to the data switch, and reversely restores the voice packets transmitted from the data switch into a PCM encoded voice signal.
That is, a voice switch, an external data switch, a separate media gateway module for interfacing the voice switch and the external data switch, and a router are needed to provide an IP-based voice communication service. Since the data switch and the router are independent pieces of equipment that, are separate from the voice switch, difficulties occur in operating and maintaining the equipment.
Also, since signaling between the existing voice switching system and the terminal is converted into an IP signal to be processed, a problem occurs in that a VoIP SIP process and an IP converted proprietary signaling process must be separated into two parts and performed separately.
Also, since the signaling between the voice switching system and the terminal can use proprietary signaling, it is difficult to provide a service connected with an existing standard SIP, and is not suitable for a communication network that evolves into an ALL IP-based Next generation Network (NgN).